Infection and response

• symptoms of the measles is a fever and a red skin rash. It is a viral disease and is spread by droplet infection. It can be prevented by vaccinations for young children.
• HIV is a viral disease that attacks the immune system and can lead to AIDS. Symptoms are initially flu-like and it is spread by sexual contact or exchange of bodily fluids such as blood. to prevent HIV, you should use condoms or not share needles.
• Tobacco mosaic virus is a virus that causes leaves to turn yellow, affecting the plant's ability to photosynthesise. It is spread between contact between diseased plants and healthy plants. It is prevented by pest control and good hygiene.
• Salmonella is a bacterial disease that causes symptoms of vomiting, diarrhoea, fever and stomach cramps. It is spread by eating contaminated food, and it can be prevented by poultry being vaccinated against salmonella and keeping raw meat away from cooked foods.
• gonorrhoea is a bacterial disease that causes thick yellow or Green discharge from the vagina or penis and pain while urinating. It is spread by unprotected sexual contact and it can be prevented by using conception.
• Rose black spot is a fungal disease that has symptoms of purple or black spots on the leaves of rose plants, which reduces the area of the leaf available for photosynthesis, leaves turn yellow and drop early. It is spread by the spores of the fungus are spread in water. It is prevented by using fungicides or stripping, the plant of affected leaves (have to be burnt).
• malaria is a protists disease, which causes symptoms of fevers and shaking. It is spread by mosquitoes and can be prevented using insect nests.
• Phagocytosis is the engulfing and consumption of pathogens, this protects you as it destroys them meaning they can no longer make you feel ill.
• By white blood cells producing antibodies, it protects you because each pathogen has an antigen on their surface, which is a structure which a specific complementary antibody can bind to. The pathogens will then start to clump together, making it easier for white blood cells to find them. If you become infected again with the same pathogen then the specific complimentary antibodies will be produced at a faster rate.
• By white blood cells producing antitoxins, they neutralise the toxins released by the pathogen by binding to them.
• a vaccine contains a dead or inactive from of the pathogen.
• Describe clinical trails

  
  

  1. Test the drug on healthy volunteers in low doses
  2. This is to check for Side effects/ toxicity
  3. Test the drug on patients (who have the disease the drug is trying to help)
  4. this is to check for efficacy /side effects
  5. The drug should go through a double blind trial where the neither the patient or doctor knows whether they are receiving a placebo or the new drug so the effect of the new drug can be observed and removes any biases.
  6. the results then need to be peer reviewed by other scientists to check for repeatability.
• Stunted growth of plants indicate nitrate deficiency
• spots on the leaves of plants indicate blackspot fungus on Roses
• areas of decay on plants suggest black spot fungus on roses
• discolouration on plants indicate magnesium deficiency or TMV
• you can identify the disease the plant has by using a gardening manual or website
• nitrate deficiency in plants causes stunted growth as nitrates in the soil Convert sugars made in photosynthesis into proteins and these proteins are needed for growth.
• Physical defences in plants, prevent the invasion of microorganisms. Physical defences can be a tough Waxy cuticle, which stops entry into leaves, cellulose cell walls form a physical barrier into the cells.
• Chemical defences in plants are poisons ( from foxgloves, deadly nightshade) deter herbivores.
• mechanical defences in plants or things like thorns and hairs to make it difficult and painful for animals to eat them. plants can also use mimicry to trick animals.
• monoclonal antibodies are identical copies of one type of antibody.
• How do you make monoclonal antibodies?

  The mouse is injected with the antigen that is being targeted. The mouse naturally produces lymphocytes which produce antibodies specific to the antigen. The lymphocytes are then harvested from the mouse and combined with tumour cells. When they are combined they make a hybridoma cells, which reproduce rapidly and produce millions of monoclonal antibodies specific to the original antigen.
• pregnancy test kits use monoclonal antibodies. These have been designed to bind with a hormone called HCG which is only found in the urine of pregnant women. Monoclonal antibodies are attached to the end of the pregnancy test stick onto which a woman urinates. If she is pregnant HCG will be present in her urine and will bind to the monoclonal antibodies on the test stick. This will cause the change in colour or pattern.